Hey all,

I'm writing with my Mini (2005) currently in the shop. She had a full workup just a few months ago and a clean bill of health but was running rough recently. The shop called to tell me they will need to look at more stuff because a prelim exam and scanning for codes turned nothing up but they agree the car isn't on par.

I'm going to describe what I've been feeling and maybe someone out there can give me some ideas, point me in the right direction or put my mind at ease (I am wondering if I need to brace for an extremely costly repair).

In gears 1-3 (especially 3) the car will accelerate, and before creeping close to 3 RPMs will sort of shudder or hiccup. I don't know a better way to describe it. I am not losing power on acceleration (I did have this problem in May, the cylinders were misfiring and we fixed it). Like I said, it is more of a knock/hiccup/shudder. I notice it almost exclusively in the lower gears.

At 40,000 miles my transmission was replaced (the car now has 125K). The clutch assembly was also replaced twice for faulty manufacturing defects. It has been a frustrating car to own. I want to love it to pieces but despite keeping up on maintenance, it seems it has one issue after another.

IN CLOSING:
Has anyone else experienced this problem? What did it end up being? Anyone with mechanic knowledge care to share some possible explanations that I can discuss with my guy? I'm biting my nails right now thinking of what it could be. :(

 

After cruising some other general BMW forums I've come up with what may be some possible suspects.

Fuel filter issue
Dying ignition coil?
Intake leaks

Do any of these sound like something anyone else has experienced?

 

If you're not losing power, what is the 'hiccup' doing, that you notice it? If it was a coil or a failed/clogged fuel filter, there would be a defined power loss, if it was an intake leak, it would happen most of the time. Unless you have a cracked valve cover or something a little bit out there like that...

 

The hiccup I suppose is a momentary loss of power. I feel like there is a pause in the acceleration and it seems a little rough or "trying harder" to get back up to speed. It is not as noticeable as when I would punch the gas and get no response for a second or so when I had a misfire problem. It is very subtle, not something the passenger seems to notice. The mechanic did and he's trying to figure it out. Does that make any more sense?

 

kinda, but i have no idea what that could be..... Possible that you have an adaptation problem, have you replaced the air filter? To possibly a K&N or similar? What was the fix for the misfire? and what kind of fuel are you using?

 

As I understood it, there was a leak in the head gasket allowing some oil into the cylinders causing the engine to misfire and lose power.

My mechanic said he replaced all the filters and did an oil change. I suppose he will do more tests tomorrow. I was hoping to maybe have some ideas to come to him with if he's still looking for solutions.

I only put 91 in my car and try to avoid super low cost gasoline at all cost.